Tucson police can now be assured of one thing not to do when they’re approaching a peaceful assembly.

Don’t position an armored vehicle amid the crowd and have officers clad in military-type gear pointing heavy weapons at them.

The unrest last week in Ferguson, Missouri, has proved educational for much of the country — including Tucson, with our history of sports riots — in part because of the different approaches police used. After days of sometimes-violent protests against the shooting of an unarmed 18-year-old, Missouri State Patrol officers, dressed in their usual uniforms, replaced St. Louis County officers who had been dressed in riot gear, carrying heavy weapons, driving armored vehicles and firing tear gas.

The change was like a balm to the city’s tensions.

The unrest coincided this week with street protests attempting to stop Tucson police from handing an undocumented man over to the Border Patrol and with a legal claim filed against the city by a woman knocked down by a Tucson sergeant during the Elite Eight disturbance in March.

This is an issue — how Tucson police handle crowds on the street — that will continue to challenge us.

It has long struck me that the posture of the police — whether they arrive in “soft gear” or “hard gear,” for example — matters a lot to how a crowd reacts. The juiced-up rowdies, I believe, see the riot-ready police as a reason to riot. The gear and posture may even affect how the police themselves act.

Tucson Police Department Sgt. Joel Mann, who knocked down the woman making the legal claim this week as well as another man that March night, was protecting the back side of a “skirmish line” when he lashed out. Video taken from a camera on his helmet captures his evident hostility toward people who seemed to be trying to pass by, not riot.

Reports from the ground suggest that the Missouri state patrol officers wandering among the crowd in Ferguson gave off a fraternal feeling to the crowd there that defused tensions. That good feeling continued until late Friday night, when a group of protesters looted a market, despite efforts by some in the crowd to stop them. That forced the police back into a hostile posture.

When you talk to police officers who study crowd control, they’re not too concerned about the type of gear officers use when they enter a crowd-control situation.

“It seems to be in this era, the general consensus is that police should be punching bags first,” said Steve Ijames, a retired Springfield, Missouri, police major who is an expert in crowd control. “Just because some people will react negatively doesn’t mean you shouldn’t do the right thing.”

That right thing, he said, is protecting officers who might be hit with rocks or bottles by putting them in protective gear, which he likened to an OSHA requirement. Ijames also was an expert witness on the side of Tucson police after the riots that occurred during the Wildcats Final Four appearance in 2001, and he noted that Tucson police started in “soft gear” that night.

After the UA basketball team lost in the Elite Eight last March 29, and the disturbance followed on University Boulevard, several Tucson police officers traveled to the home cities of Final Four teams to watch police deal with crowds there.

Two TPD lieutenants who traveled to Storrs, Connecticut, and Springfield, Kentucky, told me Friday that they had no great revelations that will revolutionize Tucson crowd control.

“The lesson is there is no Holy Grail,” Lt. James Scott told me.

He was in Lexington, where the crowd was large and good-natured after the Final Four game that Kentucky won, but the crowd was small and agitated after the championship game that Kentucky lost.

“A large amount of bottles were thrown at police — a complete 180,” Scott said.

Officials there cleared cars and burnable debris out of a two-block residential stretch where students tend to congregate and lined riot-gear-clad police on both sides of the street, he said. They didn’t try to stop the huge crowd from clogging the street, but they tried to stop fires from being set and arrest rock-throwers and other lawbreakers.

Fellow Lt. Eric Kazmierczak didn’t find many lessons in Storrs, a small town where thousands of students watched the games inside the university’s basketball arena. He isn’t too concerned about what officers wear and carry on crowd-control scenes, either.

“What we do, and the reason we wear what we wear, is not to go out and look like the military. It’s for safety,” he said.

Yet it was the appearance of the officers in Ferguson that caught the attention of the crowd, reporters there, and many of us nationwide. They reflected what the American Civil Liberties Union and others call the “militarization” of police forces in America since the Sept. 11, 2001, terrorist attacks.

For years, police departments have been accumulating military-surplus gear through federal-government programs intended initially to react to the threat of terrorism. Now, it’s often used in SWAT activities and occasionally in crowd control.

“In Missouri, the equipment they used far outstripped the threat,” Alessandra Soler, head of the Arizona ACLU, told me. “They had tanks and sharpshooters at a protest.

“It’s not an effective way to manage a peaceful crowd,” she said. “It provokes fear. That’s counterproductive when you’re trying to build trust in the community.”.

One of the key differences between Tucson’s sports riots and the protests in Missouri is that there the demonstrators were angry at the police themselves, not rallying for some other reason. But we are also having regular pop-up protests against the police themselves and their handing over to the Border Patrol suspected undocumented people whom they have arrested.

Last Sunday a crowd of dozens tried to prevent TPD from handing over Norlan Flores Prado to the Border Patrol. Last October, in a similar situation, Tucson police pepper-sprayed members of a crowd trying to prevent the hand-over of another man. That was followed by the protest in which demonstrators blockaded buses carrying people to immigration court.

Each of these situations, along with the UA sports crowds, has destructive potential. To avoid realizing that potential, it will be crucial that Tucson police resist militarizing their crowd-control responses, be human in dealing with crowds, and still protect themselves and those around them.

It’s not easy, but what cop signed on for an easy job?

Contact columnist Tim Steller at tsteller@tucson.com or 807-7789. On Twitter: @senyorreporter